All apples will go through a check to measure their sweetness before shipment, hence sweetness is guaranteed!
What is the difference between San Fuji and Fuji?
The biggest different point is whether it is raised with a bag covering the fruit or not.
San Fuji being raised without any paper bag is exposed to sun light. This helps to gain more vitamin and mineral, which leads to more sweetness. But because of no paper bag covered, the color is not as bright as normal fuji and texture is little rough on the surface.
On the other side, Fuji is raised with a paper bag which makes it shining and bright. The peel is thicker than San Fuji. The sweetness is slightly less than that of San Fuji apple.